Female Reproductive System Flashcards
Describe the two roles of the ovaries
- Produce gametes (oogenesis)
2. Produce steroids (oestrogens and progestogens)
Describe the medulla of the ovary
Forms the core of the organ and contains loose connective tissue, contorted arteries, veins and lymphatics
Describe the cortex of the ovary
Scattered ovarian follicles in a highly cellular connective tissue stroma
What layer covers the tunica albuginea
Germinal epithelium; flat simple squamous layer
What layer covers the tunica albuginea
Germinal epithelium; simple squamous layer
Describe the process by which oogonia are formed
Week 6 gestation germ cells from the yolk sac invade the ovaries; proliferate by mitosis to form oogonia
How are mature oocytes formed
Oogonia undergo development and division via meiosis (also termed ova)
What is oogenesis
The development of oocytes, the female germ cells, from oogonia
What is folliculogenesis
The growth of the follicle, which consists of the oocyte and any associated support cells
At what stage are there the most oogonia present in a females ovaries
7 months in utereo - around 5 million oogonia
What is atresia
An apoptosis-based process resulting in the loss of oogonia and oocytes
Name the 3 different types of follicle
- Primordial follicles
- Growing follicles (primary and secondary)
- Mature or Graafian follicles
Before birth, at what stage of meiosis does development halt in the follicles of the ovary
Prophase 1; many follicles will remain in this state for several decades
In a 20-year-old how many follicles will restart development a day
Around 15; drops to around 1 a day in a 40-year-old
What happens to a follicle if it fails to associate with pregranulosa cells
It will die
Describe the pregranulosa cells of a primordial follicle
Simple squamous granulosa cells
Describe the pregranulosa cells of a primary follicle
Cuboidal granulosa cells: zona granulosa
What happens as the oocyte enlarges during the primary follicle stage
A layer of special extracellular matrix, the zona pellucida, begins to form between the oocyte and the granulosa cells
Within a late primary follicle, what change happens to the adjacent stromal cells
They undergo an epitheloid transformation and go on to form the theca interna
What happens to the theca interna, and what does it produce and secrete
It becomes vascularised and secretes oestrogen precursors
What do the outer layers of the late primary follicle form
They remain fibroblast-like and form the theca externa
What does the granulosa cell layer begin expressing during the late primary follicle stage
Expressing receptors for the follicle-stimulating hormone (FSH)
What do the theca interna cells express during the late primary follicle stage
Receptors for luteinising hormone (LH) from the anterior pituitary
When can it be said that a secondary follicle has formed
When a space called the antrum has formed
What is the antrum filled with
Follicular fluid
How big can the largest antral follicle get
About 20mm in diameter
What is the cumulus oophorus
The ‘mound’ of cells extending from the wall of the follicle and surrounding the oocyte
What happens in the mature Graafian follicle prior to ovulation
The oocyte and a halo of surrounding cells (corona radiata) will separate from the rest of the lining granulosa cells
What happens to the largest Graafian follicle prior to ovulation
The oocyte will complete meiosis I, producing the secondary oocyte and the tiny polar body
What is the purpose of the tiny polar body
It takes the second nucleus away to degenerate
After the polar body has degenerated the second nucleus what happens to the secondary oocyte
It continues meiosis but halts at metaphase II
When will the secondary oocyte complete meiosis and form a fully mature oocyte
Only when it has been released from the ovary and fertilised by a sperm; producing a second polar body
Where does the secondary oocyte burst out from the ovary
At the follicular stigma
After ovulation, what does the follicle transform into
A corpus luteum containing:
- Theca lutein cells
- Granulosa lutein cells
If implantation does not occur, what does the corpus luteum become
A white coloured connective tissue called the corpus albicans
Name the parts of the uterine tube (from the ovaries)
- Infundibulum
- Ampulla
- Isthmus
- Uterine part
Where does fertilisation normally occur
Within the ampulla
Describe the mucosa of the ampulla
Folded and lined with ciliated cells and secretory cells (peg cells)
How many layers of smooth muscle exist in the ampulla, and the isthmus
Ampulla = 2 layers Isthmus = 3 layers
Describe the lining epithelium of the isthmus
Mostly secretory with few ciliated cells
Name the layers of the uterus (inner to outer)
- Endometrium
- Myometrium
- Perimetrium
Describe the layers of the uterus
Endometrium = inner secretory mucosa (shed during menstruation) Myometrium = 3 layers of smooth muscle, combined with collagen and elastic tissue Perimetrium = outer visceral covering of loose connective tissue covered by mesothelium
Name the 2 layers of the endometrium
- Stratum functionalis (monthly growth, degeneration, and loss)
- Stratum basalis (reserve tissue that regenerates the functionalis)
Describe the lining of the glands within the endometrium
They are lined with pseudostratified columnar epithelium
When does the proliferation phase of the endometrium last until
Around 1 day after ovulation
During the secretory phase, what do the glands of the endometrium secrete
They secrete glycogen
What is the cervix
A short cylinder with a small lumen that projects into the upper vagina
Describe the structure and lining of the cervix
Fibrous connective tissue covered with:
- Stratified squamous epithelium on its vaginal surface
- Mucous secreting simple columnar epithelium closer to the uterus
What is the epithelial transition zone in the cervix called
The squamocolumnar junction: common site of cervical cancer
What glands exist in the mucous secreting epithelium of the cervix
The endocervical glands
If the endocervical glands become blocked, what happens
They expand with secretions forming a Nabothian cyst
Name the 4 layers of the vagina
- Non-keratinised stratified squamous epithelium
- Lamina propria of connective tissue rich in elastic fibres
- Fibromuscular layer (inner circular,m outer longitudinal)
- Adventitia
How is the vagina lubricated
- Mucous from cervical glands
2. Fluid from thin-walled blood vessels of the vaginal lamina propria
How is the growth of pathogenic bacteria inhibited in the vagina
Commensal bacteria metabolise the glycogen to lactic acid
Describe the mons pubis
Skin which overlies a substantial subcutaneous fat pad, which itself overlies the pubic symphysis
What is the labia majora
Extensions of the mons pubis, with a similar structure
What glands exist in the labia major
- Apocrine sweat glands
2. Sebaceous glands
Describe the labia minora
Thin skin folds that lack subcutaneous fat and hair follicles
Where does keratinised epithelium extend to in the vagina
To the level of the hymen, where there is a transition to non-keratinised squamous epithelium
Name the two tubes of erectile tissue that exist in the clitoris
Corpora cavernosa
How many lobes make up the secretory tissue of the breast
Around 15-25: series of ducts drain to the nipples
What are the suspensory ligaments
Large condensations that extend from the dermis of the skin to the deep fascia overlying the muscle of the anterior chest wall
What is the basic functional secretory unit of the breast
The terminal duct lobular unit (TDLU)
Describe the duct system in the non-lactating breast
Terminal ductules -> intralobular collecting duct -> lactiferous duct (lactiferous sinus) -> nipple
What structure allows for the rapid expansion of the breast tissue during pregnancy
Loose connective tissue surrounding the acini within the lobule
What are secretory cells of the acinus in the breast surrounded by
Myoepithelial cells (contractile epithelial cells)
Describe the covering of the nipple
Highly pigmented, keratinised stratified squamous epithelium
Describe the structure of the nipple
A core of dense irregular connective tissue mixed with bundles of smooth muscle
During pregnancy, what do oestrogen and progesterone stimulate in the breast
Proliferation of secretory tissue and fibro-fatty tissue becomes sparse
Describe, approximately, the composition of human milk
Water = 88% Carbohydrate = 7% (mainly lactose) Protein = 1.5% (mainly lactalbumin and casein) Lipid = 3.5%
Name the 2 different types of secretion in the breast
- Apocrine
2. Merocrine